Exposure mask and method for divisional exposure

An exposure mask and a method for divisional exposure are provided to advantageously reduce or eliminate stitch defects in displays. In one embodiment, an exposure mask comprises a masking panel and a slit for selectively transmitting light from a light source, the slit including a taper portion such that an area proximate the taper portion transmits less than full light intensity onto a substrate to be masked. In one example, the area proximate the taper portion is bounded between an inner corner and an outer corner of the taper portion. In a further example, the area proximate the taper portion transmits substantially one-half the light intensity onto the substrate to be masked. A method of divisional exposure utilizing the advantageous exposure mask is also disclosed.